Locomotive draft appliance



D. F, CRAWFORD. LOCOMOTWE DRAFT APPLIANCE. APPLiCATlDN FlLED MAR. 3 1919.

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` Afin/ways DAVID F. CRWORD, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 LOCOMOTIVE STOKER COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION 0F PENN- y SYLVAN IA.

I LOCOMOTIVE DRAFT APPLIANCE.

.;=.;cation filed March 3,

To all whom it may conce/ML.' v

Be it known that I, DAVID F. CRAWFORD, a citizen of the United States, residing at Pittslnlrgh, in the county of Allegheny and State of Pennsylvania, have invented'certain new and useful Improvements in Locomotive Draft Appliances. of which the fol lowing is a specification.

This invention relates to draft appliances and particularly to that class of apparatus in whichA draft is created by a blower fan operated by a turbine or otherv form of engine, utilizingl exhaust steam.

Heretofore, in this class of apparatus all of the exhaust steam is passed through the turbine, as a result of which it is impossible to maintain proper draft conditions, particularly when the locomotive is working hard, in which case the turbine would rotate at too high a rate of speed, thus greatly increasing the draft and causing popping or waste of steam insome instances, and in others pulling the lire out of the box.

It is one of the primary objects of my invention to overcome the foregoing difficulties and to provide an improved apparatus whereby the draft may be simply` regulated to suit Iall operating conditions. MyJinvenL tion also contemplates an improved arrangement of the draft appliance whereby back pressure is substantially eliminated.

I accomplish the foregoing together with such other objects as may hereinafter appear, by means of a construction which I have illustrated in preferred form in the accompanyingV drawings whereinigure 1 is a longitudinal section through the smoke box of a locomotive showing my improvements applied thereto; and Fig. 2 is a transverse section taken on the line ,II-II of Fig. 1.

In the drawings I have shown my improvements'in connection with a blower apA- paratus ofV the. steam turbine type. The smoke box' is indicated as a. whole at A and the draft appliance comprises a. blower fan 7 carried on the shaft 8 of a steam turbine 9, which may be located inside or outside of the smoke box. The blower fan operates inl the usual .manner and sets up a draft which draws the products of combustion from the. lire box through the lues into thesmolre box the cinders being caught b a series of baflies, indicated as a whole at The .detail construction of Phe internal mechanism Specication of Letters Patent. Patented Oct, 26, 1920.

1919. Serial No. 280,295.

of the turbine 9 forms no part of the present invention. l

Exhaust steam from the cylinders is led into the passageway 11 of the casting 11a. The passageway 11 opens into a passageway 12 which communicates with the annular steam chamber 13 of the turbine, and into a passageway 14 which communicates with a'bypass 15, varranged exteriorly of the turbine. The two passageways 12 and 14 are preferably controlled by a single rotary valve element 16. At the top, the bypass 15' is provided with a discharge outlet 17, and

erative when no special draft is necessary.

0r thevalve may be shifted to entirely un.

cover passageway 12 andA close eratio of the locomotive obtained.

to largely or substantially eliminate back pressure.' In this connection I prefer to construct the passages 12 and 14 and the chambers-18. and 15 with no restrictions in area relative to the area of the exhaust essa es from the cylinders, so that substantially te v only back pressure created is the-slight pres v' l sure incident to turning the turbine and fan,

which is negligible as a matter v,of ordinary practice. v 5. l

I claim :-'--A thus rendered inopsol I h passageway 14, in wlnch position the turbine and fan.

proper manipulationof theyalve, v the operatingconditions and ellcient ,and economical 'opy- .v

' 1. A locomotive draft appliance compris;

ling in combination a draft producing means, an engine for driving the Same operated Vby eol It will 'be seen therefore, that l It is also to be observed that I-am'enabled exhaust steam from the cylinders, means for conveying the steam thereto, and means bypassing the steam.

2. A variable locomotive draft appliance comprising in combination a draft producing means, an engine -for driving .the saine.

operated by exhaust, steam froml the cylinders, means for conveying the steam thereto,

and means for varying the drait comprising means for bypassing steam.

3. A loeomotive draft appha-nee -eoi'nprlsking in combination a draft producing means,

an engine for operating the same utilizing exhaust steam from the cylinders, the appliance being provided with two passages, one for conductingthe steamlto the engine and the other for by-passine the steam, and a valve controlling` both passa-ges.Y

5. i loconiotive draft appliance comprising in combination a draft producing means, and au engine for operating the same utilizing' exhaust steam, theI appliance being pro vided with a tonduit for conveying steam lto the engine and with hy-passing means substantially unrestricted in area relative t0 the area ot the exhaust passages'rom the cylinders. 4

ln testimony whereof, `I have hereunto signed my naine.

l DAVID if. onAWFoRD. 

